January 11th, 2018

October 31st, 2017

Computational treatment of Indian languages: problematics.
International Seminar on Paradigm Shift in Indian Linguistics and its Implications for Applied Disciplines. Indian Institute of Advanced Study, Shimla, India.
Talk (pdf).

April 28th, 2016

Programming Methodology and Type Theory.
How 40 years of uncompromising research made concrete the Chalmers
futuristic vision into the Software Engineering paradigm of
Programs correct by construction.
Meeting in honor of Bengt Nordström, Marstrand.
Sildes (pdf).

November 6th, 2015

November 4th, 2015

The Sanskrit Heritage Platform.

Abstract.
We present a short demonstration of the Sanskrit Heritage Platform, a set of inter-connected Web services using functional programming.
It is an exemple of Numerical Humanities for Cultural Heritage management, based on Computational Linguistics technology.
Its core component is the Zen toolkit, a small library for computational linguistics using a relational programming methodology.
The Zen library is very small (4000 lines of pure functional programs). It may be presented as an executable course in the technology, using a literate programming presentation of the code itself.
The full platform is a more consequent software endeavor (40K lines in 100 modules). Nevertheless, its full source can be issued in the same manner as a complete
readable document explaining the linguistic processes in terms understandable by a Sanskrit grammarian. The lexicon itself is available as a Hypertext document presenting Sanskrit meanings in the cultural context of ancient India.
This platform is free open source software, and has interfaces with a community
of related interoperable platforms.

August 25th, 2014

Febuary 8th, 2014

Semi-automatic analysis of Navyanyāya compounds.
Special session on "Recent Developments in Sanskrit Computational Linguistics"
at the 30th Round Table of South Asian Language Analysis (SALA),
University of Hyderabad.
[Presentation by co-author S. R. Arjuna]
Slides (pdf).

January 23th, 2014

30 Years of Research and Development around Coq.
SIGPLAN Software Systems Award session,
41st ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages
(POPL) San Diego, USA.

January 16th, 2014

From lexical trees to effective Eilenberg machines: the Zen toolkit for computational linguistics.

Abstract.
The Zen toolkit is a library in the functional programming language OCaml,
oriented towards computational linguistics tasks.
Its main data structure is a generic notion of decorated lexical tree, spanning
the spectrum between lexicon structures and finite machines transition graphs.
Zipper technology allows fast update of such structures in an applicative manner,
while the sharing functor yields their optimal compression.
A notion of differential word permits crisp representation of morphology
as an editing distance. A reactive engine drives non-deterministic search
in a fair and efficient manner. These simple concepts generalize to a general
notion of relational programming with effective Eilenberg machines.
We shall demonstrate the effectiveness of this technology for Sanskrit
segmentation.

April 5th, 2012

Abstract.
The Sanskrit Heritage engine is a software platform combining a lexicon usable
both as a hyper-text Sanskrit dictionary for human users and as a morphological
generator for inflected forms, a text segmenter based on finite-state
technology, and a shallow parser based on semantic roles analysis. The global
architecture of this platform is that of interconnected web services allowing
interaction with digital libraries and other external resources.

January 6th, 2012

Departing from Paa.nini for good reasons.
15th World Sanskrit Conference, New Delhi, India.

October 22nd, 2011

September 17th, 2011

Computational linguistics for Sanskrit: presentation of the Sanskrit Heritage platform.

Abstract.
We present the current status of a computerized platform for processing Sanskrit text. It consists in a structured lexical database,
the Sanskrit Heritage Dictionary (currently 21000 entries, of which 580 verbal roots, generating ~8 lakh forms), and a set of interconnected
Web services allowing kṛdānta generation, inflected forms generation, lemmatization, sandhi viccheda, morphological tagging, and shallow parsing.
The talk will demonstrate the system on characteristic examples, will discuss the software architecture and its limitations, and will
survey ongoing cooperative work with the Sanskrit Studies Department of the University of Hyderabad and the Sanskrit Library effort.

January 14th, 2010

December 23rd, 2009

Architecture design of the Sanskrit Reader.
National Workshop on Sanskrit and Computers:
Getting Equipped to Face New Challenges. Sanskrit Studies Department,
University of Hyderabad.

December 21st, 2009

Using Computational Linguistics Technology
for Sanskrit Understanding.
National Workshop on Sanskrit and Computers:
Getting Equipped to Face New Challenges.
Sanskrit Studies Department, University of Hyderabad.

November 17th, 2009

October 12th, 2009

Relational Programming.
Department of Computer Science, University of Texas at Austin, USA.

Abstract.
We present in this talk a new paradigm for relational programming,
using a concept of "Effective Eilenberg Machines".
Eilenberg machines were defined 35 years ago by Samuel Eilenberg
as a generalisation of finite state automata, which has not so far attracted
the attention we think it rightly deserves. An Eilenberg machine consists
in two components. Its control component is similar to a non-deterministic
finite state automaton,
whose transitions are labeled with symbols from a set of action generators.
Its computation component consists in a semantic attachment of actions generators
to binary relations over some data domain. These relations are effectively
presented as algorithms mapping a data value to a lazily computed stream of
related data values.
Such machines are doubly non-deterministic, and may be simulated by a
sequential reactive engine which completely explores the state space.
Various meta-theoretic properties lead to a variety of exploration strategies.
For instance, an important family of Finite Eilenberg Machines enjoy an
efficient simulation by a purely iterative bottom-up search. Effective Eilenberg
Machines define a characteristic relation over their data domain, which may be
used as semantic assignment for higher-level machines, leading to a concept of
composition of modular machines. A high level language extending regular
expressions permits the applicative description of the control component,
compiling into finite-state automata. An equational semantics axiomatizes
the machine actions within V. Pratt's action algebras, an equational variety
which is a conservative extension of Kleene algebras. This conceptual
apparatus has been developed as joint research with Benoît Razet.

Dec 21st, 2007

Sept 24th, 2007

Design of a computational linguistics framework along applied mathematics principles.
Department of Computer Science and Engineering, Chalmers University of Technology,
Göteborg, Sweden.

Abstract.
The author designed a platform for the analysis of the Sanskrit language using a number of tools,
mixing a generative aspect (synthesizing linguistics resources) and an analytic aspect (solving symbolic
constraints idealizing some semantic consistency of the analysed sentence). The talk will consist in a
demonstration of this platform, followed by the discussion of a proposal for guiding the design of such
linguistic assistants along general modeling principles inspired from applied mathematics.
The generic view is that understanding natural language by computer ought to be viewed as solving
the inverse problem of speech production, putting as a central investigation its parameters identification.

May 2000

Archeology

July 28th, 1996

The next 700 Proof Assistants.
Invited Lecture, Federated Logic Conference FLoC'96.
This lecture is famous for having introduced the zipper concept
and for the strong reactions this presentation evinced.
Since some of the material in the talk was never published, specially
regarding the use of Regular Böhm Trees for sequent calculus
implementation, I offer here the
slides of the talk.
The slide that provoked the scandal is the one between slide 14 and slide 15.
I rest my case.

This event marked the end of my active research period into logic and the
mechanization of mathematics.
A few months afterwards I took a managerial position at INRIA's Direction
Générale as Head of International Relations. When I returned
to the lab in the next century, I started my work in Computational Linguistics.

June 16th, 1987

Canonical basis of commuting diagrams - Application
to the mechanical synthesis of coherence conditions .
By some miracle, the 1987 slides survived, and a fac-simile is available
as a pdf document.
This lecture is famous for having infuriated William Lawvere beyond control.
It marked the end of my interest for category theory and its psychopaths.